Solar Wire Sizer

Solar Wire Sizer helps solar energy professionals select the correct wire size for PV systems based on NEC standards.

FEATURES:
- Wire sizing per NEC Table 310.16 ampacity ratings
- Max circuit current per NEC 690.8(A)(1): Isc x 1.25, then both printed 690.8(B) checks: base ampacity vs 156%, corrected ampacity vs 125%
- Voltage drop calculation with configurable thresholds (2-3%)
- Temperature derating per NEC Table 310.15(B)(1)
- Copper and aluminum conductor support
- DC, AC single-phase, and AC three-phase circuits
- 60C, 75C, and 90C insulation temperature ratings
- Wire sizes from 14 AWG to 500 kcmil

NEC COMPLIANCE:
- NEC 690.8(A),(B)(1),(B)(2) - PV circuit current and two-step conductor ampacity
- NEC 690.31 - Methods permitted for PV wiring
- NEC Table 310.16 - Allowable ampacities of insulated conductors
- NEC Table 310.15(B)(1) - Ambient temperature correction factors
- NEC Chapter 9 Table 8 - DC resistance values

OPTIONAL PRO UPGRADE - $2.99 ONE-TIME IN-APP PURCHASE
The following features require a separate one-time in-app purchase. They are not required to use the calculator:
- Unlimited saved calculation history
- PDF export of results
- Dark theme
- Ad-free experience

UPGRADE TO PRO:
- Remove banner ads
- Unlimited calculations
- Dark theme support

Designed for solar installers, electricians, and PV system designers working in the United States.